Jupiter and Saturn, and there are suspicions that they partake
something of the character of the sun, and emit some light besides
reflecting solar light. On both planets some absorption lines seem to
agree with the aqueous vapour lines of our own atmosphere; while one,
which is a strong band in the red common to both planets, seems to
agree with a line in the spectrum of some reddish stars.

Uranus and Neptune are difficult to observe spectroscopically, but
appear to have peculiar spectra agreeing together. Sometimes Uranus
shows Frauenhofer lines, indicating reflected solar light. But
generally these are not seen, and six broad bands of absorption
appear. One is the F. of hydrogen; another is the red-star line of
Jupiter and Saturn. Neptune is a very difficult object for the
spectroscope.

Quite lately [7] P. Lowell has announced that V. M. Slipher, at
Flagstaff Observatory, succeeded in 1907 in rendering some plates
sensitive far into the red. A reproduction is given of photographed
spectra of the four outermost planets, showing (1) a great number of
new lines and bands; (2) intensification of hydrogen F. and C. lines;
(3) a steady increase of effects (1) and (2) as we pass from Jupiter
and Saturn to Uranus, and a still greater increase in Neptune.

_Asteroids_.--The discovery of these new planets has been
described. At the beginning of the last century it was an immense
triumph to catch a new one. Since photography was called into the
service by Wolf, they have been caught every year in shoals. It is
like the difference between sea fishing with the line and using a
steam trawler. In the 1908 almanacs nearly seven hundred asteroids are
included. The computation of their perturbations and ephemerides by